Moa

Discussion in 'General Rifle Discussion' started by austin92, Jan 22, 2013.

  1. austin92

    austin92 New Member

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    Can you guys please help me understand moa? Ive spent an hour on YouTube and a couple on google and still can't wrap my head around it and how to properly use a mil dot scope. I want to become a more proficient long range shooter and make the right choices when purchasing scopes. From what I've gathered so far one moa=1" at 100yds but idk how that's true for different cartages as they should have different flight paths, right? This is just confusing as hell but it's something I'm determined to learn. Also been reading up on mil dots as something to consider that may help with long range shots. That's a whole nother story I'm completely lost on
     
  2. dog2000tj

    dog2000tj New Member

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  3. hoovco

    hoovco New Member

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    1 MOA is roughly 1" at 100 yards. MOA is minute of angle, which is one 60th of a degree. So when you make a 1/4 MOA adjustment, you're really compensating for 1/240th of a degree at your position, equating to a quarter inch at 100 yds.
     
  4. hoovco

    hoovco New Member

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    Once you find a load you like to use, make a little chart as a pocket reference and list your bullet drops and wind values. It's pretty handy. I have one for Federal GMM 168GR SMK and M118LR.

    Mil dot math is pretty easy once you get used to doing it. After working with a load you like, you'll start to memorize all your holds/ adjustments.
     
  5. headhunter

    headhunter Member

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    MOA is 1.1 inches at 100 yds. The milrand is based on there being 360 degrees in a circle.
    You will need a long range to actually test what is happening when you squeeze the trigger. You set your "zero" at , say 100 yds. this is one way. If your target is at a range where your testing has shown you need an adjustment of 10 ", you move your elevetion dial an amount equal to the ten inches and you hit your target using the crosshairs. Should you want to be quicker you raise the crosshairs so you are on the 9th mil dot below the crosshairs and squeeze. See, mil dot and inches are not equal.
    I don't have this range so I find a chart (as some posters have pointer out) in a reloading manual.
    To use this well, you will need to know where the rifle is sighted in for, the caliber or the balistic coefficient of the bullet, and the actual velocity of the bullet. In the best of printed tables there are some assumptions made (eg. the distance between the axis of the bore and the line of sight through the scope usually assumed to be 1 1/2" or velocities are rounded off).
    Serria reloading manuals have a good chart,but you must know your velocity (actual- not claimed) and caliber/bullet wt. Then you must have your rifle sighted in for the excact range in/on the chart. As a previous poster said put this on a card taped to your butt stock.
    The next part is a little harder, how far is you target away? Rangefinder time or there are some clues. When riding in the country most telephone poles are 98 yds. apart, use this to get practice judging how far things are away-a tree, a sign---. The military makes small pics with distances before a target shows.
    The last part is harder yet, what effect will the wind have? They sell hand held anemometers or meterologists learn to use natural phenonia to judge wind speed (Beaufort Scale- are leaves moving or blowing, how big are the branches the are blowing). Make sure you put wind drift on your chart. If it is a quartering wind cut your dift in half.
    I hope I haven't really messed you up. Last if you are shooting up hill or down hill at an angle of 45 degrees, cut your bullet drop in half.
     
  6. trip286

    trip286 New Member

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    Question on this detail: you think that may be because the military uses meters instead of yards?
     
  7. JTJ

    JTJ Well-Known Member Supporter

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    I think you have MOA confused with POI (point of impact). Different calibers and different loads within the same caliber will have different trajectories also referred to as bullet drop. MOA remains constant as it reflects 1.1" at 100 yards, 2.2" at 200 yards etc. Keep in mind that the mil dots will only be accurate at one power setting, usually but not always 10X, and all calculations have to be based on that one setting.
     
    Last edited: Jan 22, 2013
  8. hoovco

    hoovco New Member

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    You can use meters or yards in mil dot equations.

    The equation is
    (size of target in meters x 1000)/ size of object in mils = range to target in meters

    It works because you're measuring your target with the same unit that you're using to determine your range.

    A mil just happens to be 1 yard at 1000 yards/ 1 meter at 1000 meters. So if you have a midget that stands 3 feet tall, he'll measure out to be 1 mil at 1000 yards.
     
  9. austin92

    austin92 New Member

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    Thanks for the input guys. Think I might take the .22 mag out and play around with the scope and a note pad. I'm more of a hands on learner but there's some good info here to go off
     
  10. hoovco

    hoovco New Member

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  11. austin92

    austin92 New Member

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  12. Txhillbilly

    Txhillbilly Active Member

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    That isn't true.
    On a First Focal Plane scope,the mil dots measurement value remains the same through out the entire magnification range.
    And,you can use several different magnifications on most Second Focal Plane scopes if you are good at math,or make range cards with the particular measurement spec for the mil dots at a given magnification.
    I can use 6/8/10/12/16/18/20/22 or 24 power to range with my Sightron SIII scopes,but each power uses a different measurement between the mil dots.

    The main thing about choosing a mil dot style scope is you need to match the Turrets with the Reticle. You need either a Mil/Mil or MOA/MOA turret/reticle scope to really use the scope for ranging.
    Most lower tier scopes don't offer a matched turret/reticle set-up,they have MOA turret marks,and use a Milliradian reticle.
    That makes it harder to calculate the distance/scope adjustments for long range shots.
     
  13. austin92

    austin92 New Member

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    What are some good scopes with the mil dots or the moa dots for someone just starting out in long range shooting? I'd really like something that locks and unlocks an easy adjust turret unlike the ones I have that require a coin or screw driver
     
  14. sniper762

    sniper762 New Member

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    DO NOT use hold over...........know your rifle/load combo ballistics and DIAL in your scope adjustments to compensate for target distance
     
  15. austin92

    austin92 New Member

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    A lot of why I wanted one with turrets that adjust so easily
     
  16. hoovco

    hoovco New Member

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    I think some of that is personal preference. If you have the time to twist dials and all that jazz, that's one thing. I know a guy that was doing holds on a cloud to hit targets on the side of a mountain. It's not like one is better than the other.
     
  17. sniper762

    sniper762 New Member

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    i was taught to make the FIRST round count.............there may not be a chance for a second
     
  18. hoovco

    hoovco New Member

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    Yeah ... and? So a hold is less accurate how?
     
  19. hoovco

    hoovco New Member

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    Even though I prefer to dial in as well, I don't see how a hold is less accurate. If you know your load and your holds/ adjustments, it's user error if you miss either way.